US President Donald Trump on Thursday ridiculed as "phony" and "witch hunt" claims about collusion between Russian Federation and his associates after media reports that he is being investigated for possible obstruction of justice. Yet two months later, he played a direct role in Trump's decision to fire Comey, citing Comey's handling of the Hillary Clinton email investigation during the 2016 race.

"Declining to answer questions at a congressional hearing about confidential conversations with the President is long-standing executive-branch-wide practice", the DOJ official said in a statement. "We are not in a position to comment further".

In an off-camera 18-minute gaggle held Thursday, deputy press secretary Sarah Huckabee Sanders seemed to infer that she was barred from the discussing the tweets President Trump fired off earlier that morning.

A separate investigation into Russian Federation has also reportedly focused on potential use of offshore banking centers to launder money.

Trump punched back a day later, telling reporters Comey had lied under oath, saying: "Frankly, James Comey confirmed a lot of what I said, and some of the things that he said just weren't true".

According to a Washington Post report, the move to investigate President Trump's conduct marks a major turning point in the investigation, which until recently focused on whether there was any coordination between the Trump campaign and Moscow.

Trump was forced to fire Flynn in February after he misled the White House about his contacts with Russian officials a year ago as a member of Trump's transition team.

The Senate intelligence committee has also interviewed Johnson in connection with its investigation of Russian activities during last year's election campaign.

Trump reportedly asked both Coats and Rogers to publicly say there was no evidence of collusion, while Ledgett wrote a memo detailing the conversation Trump had with Rogers. "That's Bob Mueller's job to sort that out". But Comey did lay out facts that a prosecutor could use to try to prove obstruction, as NPR's Domenico Montanaro noted.

He also contradicted a contention made by Mr. Comey at a hearing before the same panel last week.

When asked about his conversation with Comey on the day the president spoke to Comey alone, Sessions described the exchange differently than the former Federal Bureau of Investigation chief did in his testimony last week.

As for the probe into his former national security adviser Michael Flynn, he said Mr Trump told him: "I hope you can let this go".

Sessions maintained that he had not been briefed on the Russian Federation investigation between the time of his February swearing-in and his March 2 recusal.

Trump is not the only one under scrutiny, Barrett said: Investigators are also looking into the finances of Trump associates. But he did not provide much enlightenment for those who followed the saga of Russia's alleged meddling in the election in 2016 closely. He added that fundraising records show some of the lawyers whom Mueller selected for his team have contributed to Democrats. It (obstruction of justice) is a hard case to make. At the end of May, the chief of the Justice Department's Fraud Section, Andrew Weissman, also joined the team, NPR's Carrie Johnson reported at the time.